This invention relates to the purification of phenol produced by the oxidation of cumene, more specifically, the removal of acetol and alphamethyl styrene from crude phenol by reaction in the presence of a catalyst, to purify for the subsequent hydrogenation of phenol process.
Production of phenol by oxidation of cumene is known, such as in U.S. Pat. No. 3,290,384 hereby incorporated by reference. The subsequent hydrogenation of phenol to cyclohexanone is known, such as in U.S. Pat. No. 3,076,810, or for the vapor phase process, U.S. Pat. No. 3,305,586, both hereby incorporated by reference. Various processes for purification of phenol prior to hydrogenation are also known, such as in U.S. Pat. No. 3,965,187; U.S. Pat. No. 2,992,169 and U.S. Pat. No. 3,692,845, all hereby incorporated by reference.
Phenol produced by the cumene oxidation process contains constituents which lower the rate of hydrogenation relative to a purified phenol. Additionally, these constituents generate carbon monoxide. Carbon monoxide is known to deactivate the catalyst used in the phenol hydrogenation process (palladium on carbon or other support). When the phenol produced from cumene was pretreated with diand polyfunctional aliphatic, alicyclic or aromatic amines and then distilled, the harmful constituents were apparently removed as the rate of hydrogenation was relatively high and only very small amounts of carbon monoxide were generated during the hydrogenation reaction.